File body



Dec. 23, 1952 J, KERN 2,622,311

FILE Bony Filed Nov. 24, 1950 E. 777" v irirv n 1. $1 IIIIIIIIIIIIIIIIIIII/lz.

Ta 110 I: K9. v m INVENTOR ATTORNEY-i Patented Dec. 23, 1952 FILE BODY Jakob Kern, Zurich, Switzerland Application November 24, 1950, Serial No. 197,302 In Switzerland December 7, 1949 1 Claim. 1

This invention relates to improvements in file bodies, i. e. tools for removing parts of work pieces by a chipping action exerted by means of a file.

The main object of the invention is to provide a cheap filing tool readily adapted for use in a filing machine.

With this object in View the file body according to the invention comprises a cylindrical piece of steel tube having its outer surface provided with file recesses and means adapted to mount said tube coaxially on a rotary driving spindle, said means being secured to said tube.

In the drawings an embodiment of the invention is shown.

Figure 1 is an isometric view of the file body. Below this view a tubular work piece having an end surface tooled by means of said file body has been shown.

Figure 2 shows in axial section a file body fixed to a rotary driving spindle of a filing machine.

The file body comprises a simple piece of steel tubing I, the outer surface of which has been formed like a file surface before hardening by providing sharp-edged grooves, which extend along the cylinder generatrices. In one end of the piece of tubing I, which at its edge has been provided with a recess 2, a perforated steel disc 3 has been secured e. g. by pressing. Said disc is seated against a shoulder 4 (Fig. 2), formed by boring said end of the tube. The annular front surface of the other end of the piece of tubing I has been inwardly and conically tooled to form a seat 5 for a cone 9 and the edge surface of the piece of tubing forms an annular seat 6, which lies in a plane perpendicular to the axis of the tube.

As shown in Figure 2 said file body is coaxially mounted on a rotary driving spindle during operation, said spindle carrying a drivin plate 8 of a driving device and at its free end being provided with a conical screw nut 9. The conical surface III of the nut 9 finds its seat on the conical edge surface 5.

In a radial groove of the driving plate 8 of the driving body 8 a cam l I has been fixed, which extends in the recess 2 of the file body. The boss [2 of the driving plate 8 corresponds diametrically exactly to the central aperture in the centering disc 3 of the file body. By means of the seats 5 and 6, as well as the centering disc 3, said file body is perfectly and coaxially fixed on the driving spindle for the rotation.

The described file body can easily be manufactured in several sizes with a minimum of cost thanks to the application of a piece of tubing as cheap raw material, whereas the otherwise delicate boring operation for the manufacture of such a perforated cylindrical file body from solid steel cylinders is avoided.

Said file body in particular makes it possible (as is shown in Fig. 1), that an end of a tubular work piece is quickly filed for an exact fitting to another tube, which has to be connected at an angle with said tubular end.

Having now described my invention and the objects thereof, what I claim is:

A file body comprising a cylindrical steel tube having its outer surface provided with file recesses, one end of said steel tube part having a perforated disc secured therein, said end of the steel tube being provided at the border thereof with a recess adapted to locate a cam of a rotary driving spindle, the front edge of said steel tube opposite said disc being tooled as a seat for a conical corresponding surface of a fixture.

J AKOB KERN.

REFERENCES CITED UNITED STATES PATENTS Name Date Cote Feb. 11, 1873 Number 

